Oil circuit breaker



c. AALBORG 1,930,026

OIL CIRCUIT BREAKER Filed Nov. 17, 1927 2 Sheets-Sheet l -Oct. 10, 1933.

w 5 I E 'ATTORNEY Oct. 1o, 1933.

C. AALBORG OIL CIRCUIT BREAKER Filed Nov. 17, 1927 2 Sheets-Sheet 2 l /6 jl-"l 20 4 *l 5 i & j

- im f INVENTOR ATTORNEY Patented. Get. 10, 1933 1,930,026 v Y oI'L CIRCUIT BRAK'ER j' Christian Aalborg, Wilki'n'sburggl Pa assigner to Westinghouse Electric &'Manufactu`ring Com-` pany, a corporation of'Pennsylvania Application November 17, y1927 Serial No. 233,846

Claims. (Cl. 20C-150) My invention relates tocircuit interrupters and more particularly to oil-immersed circuit interrupters of large capacities.

One object of my invention is to provide means 5 within the circuit interrupter that shall minimiao the stresses on the supporting structure oi' the forces which frequently-accompany the open'u ing of. the circuit interrupter.

Another object of my invention is to provide a partition within the'circuit interrupter that shall be positioned below the vsurface of the contained fluid.`

A further object of my invention is to provide a partition below the fluid level of a circuit -interrupter that shall prevent the :said iiuidffrom being thrown upward in a body and that shall therefore result kin equal forces being present in all directions Awhen the circuit interrupter is opened.

A still further object of my invention is to provide a partition below the surface of the `luidin a circuit interrupter that shall provide communication with the upper air chamber through small openings and passages, whereby the interior pressure caused by arcs incident to the opening of the load current may be slowly dissipated. f l

Heretofore diiii'culty has been experienced in the circuit interruptor artv due to the supporting 39 structure becoming strained and loosened by repeated operation. In analyzing the forces present in the circuit' interrupter `to ascertain the source of these strains, it was found that the pressure present due to the gases formed by the arc incident to opening the circuit interruptor caused the oil to move upward in a body. The reactive force to this movement causing a downward thrust on the bottom of the tank followed by an upward thrust when the said body of oil came in contact with the top cover member.

In practicing my invention, I provide ay parti-j tion or a secondary cover below the level of the surface of the fluid which prevents the oil from moving upward inv a body and results in equal pressures being exerted by the gases inall directions, thus eliminating the alternate downward and upward `forces presentin circuit interrupters heretofore employed.

Referring to the drawings, Figure 1 is a side view, in section, of a particular embodiment of my invention,

2 is a similar view, taken 90 from the View shown in Fig. 1.

My invention comprises, in general, a tank 1 that contains an insulating iluid 2, having a cover member 3 and a partition 4 that is supported by the cover member 3 and immersed in the linsulating liquid 2 below the level of the surface of the said liquid.

The tank 1 is supported from the covermember 3 vby bolts 10 and hasta lining Scooperating with its inner wallto insulate the arc therefrom. The cover member also a means for supportving bushings l6 andv'?` (Fig. 2) that terminate in contact members 8 and 9, respectively, within the lower part of thetank 1. Aliit rod 11 supports, at itslower extremity, a bridging member l2 carrying the separable electrical contacts of the circuit interruptor, ,the upper end `passing through an aperture 13 of the cover member 3. A spring` support member 14 is suspended .on the lift rod 11 and abuts against a spring' 15 that is compressed when the circuit interrupter is closed and is employed `toincrease the speed ofl opening' of the'bridging member 12.*V` The cover member 3 is supportedupon a supporting structure 16 and is bolted thereto by bolts 1'7 and 18. It will thus beseen that the supporting structure 16 is Vthe means for supporting the entire circuit interrupter through the covermember;

The partition 4 may be of any shape, and is shown herein in the shape of a dome,l of a diameter slightly smaller than that 'of the inner wall of the tank. vThus there is clearance 19 between the side Wall of the partition 4 and the inner wall of the tank 1. An annular ring 20 is welded to the outer edge of the partition 4 and contains `apertures 21 located at different intervals on closed ,positionr with the contact members vclosed as shownin the drawings, upon the release of the retaining mechanism (not shown) the bridging member 12 is thrust downward-into the position shown in dotted lines in 2, which movement is accelerated by the release of the energy stored `in the spring l5. The gases formed by the arc drawn by this movement will create apressure within the liquid which will be `distributed evenly in all directions, tobe slowly dissipated by the passage of the gas and someofj the oil through the apertures 22,23 and 24. ,The tank structure,

the cover, and the bolts are designed ofrsuicient two impacts neutralize and produce no net forcer external to thevtank. For this reason, the partition 4 may well be, in shape, the geometrical image of the tank bottom.

It will thus be seen that I have .been able to eliminate the stresses in the supporting structure of a circuit interrupter by preventing the movement of the oil upward in a body against the cover member, vthereby preventing a downward thrust of the tank l. followed by an upward whip that heretofore stressed the anchor bolts of the supporting structure, and the supporting arms of the cover member supported thereto.

It is to be further noted that while this design does not decrease the amount of force'present between the tank and the cover member', less damage is likely to result as a result of eliminating the shock that was heretofore present when the bodyof oil struck the cover member.

It is to be understood that such changes in the form, arrangement and connection of the component parts of my invention may be made as shall fall within the scope of the appended claims.

I claim as my invention:

1. The vcombination with a tank containing a quenching liquid, of a cover therefor, a partition substantially parallel to the cover and rigidly suspended-therefrom below the surface of the lliquid, and an annular wall on the partition forming a tortuous path for the liquid between it and the said tank.

2. The combination with a tank having a bottom of substantially dome shape and containing a quenching liquid, of a cover therefor, and a meinber of a shape similar to that oi the said bottom but inverted relative thereto and rigidly suspended below the surface of the saidl liquid.

3. The combination with a tank containing a quenching fluid and separable contacts, of a cover member for supporting the said tank and contacts, including a concave member positioned below the level of the surface of the said fluid and constituting substantially the geometrical image of the tank bottom.

4. The combination with a tank for enclosing separable contact members of a circuit interrupter, of a quenching fluid therefor contained within the tank, and a curved partition within the tank in opposed relation with the tank bottom and constituting the geometrical image thereof and positioned below the surface of the said liquid above the contact members;

5, In a switch mechanism having a tank containing a quenching iluid and separable contact members wherein large pressures are present when the contact members are separated, a sup porting structure for the said tank and means comprising a partition within the tank positioned below the-surface of the fluid in such a manner that the contact members are substantially midway betweenthe pariition and the bottom of the tank to equalize the stresses produced by the said interior pressure.

6.- A circuit interruptor including a housing having a cover and containing an insulating liquid, separable contact members immersed in said liquid and enclosed in said housing wherein large pressures are developed upon circuit interruption, a supporting structure for said housing, a partition carried by the cover of the housing and disposed above the contacts and below the surface of the liquid, and means for opposing the downward force on the bottom of the housing, imposed by said liquid upon circuit interruption,

by the upward force of said liquid on said partition, said means including the cover, the housing, and means connecting the cover to the housing through which said forces are transmitted and Yimposed against each other, whereby stresses transmitted to the supporting structure upon circuit interruption are minimized.

7. A circuit interruptor comprising a housing having a cover and containing an insulating liquid, means for securing the housing and the cover together, separable Contact members irnmersed in the liquid within said housing, a supporting structure ior the housing, and means for applying the upward force of the liquid above 'the contact members, developed upon circuit interruption, to the bottom of the tank to neutralize the downward iorce of the liquidV thereon, said means including a partition carried by the cover and disposed below the surface of the liquid and above the contact members, the upward force being transmitted from said partition through the cover, the securing means and the housing to the bottom thereof to neutralize the downward force thereon, whereby stresses imposed on the supporting structure upon circuit interruption are minimized.

S. A circuit interrupter comprising a housing having a cover and containing an insulating liquid, means for securing 'the housing and the cover together, separable contact members immersed in the duid within said housing, a supp structure for the housing, and means for applying the upward force on the liquid above the contact members, imposed thereon upon circuit interruption, to the bottom of the housing neans includiniT a partition disposed below the vel oi the liquid and above the contacts, the :ecuring means and the housing through which s id forces are transmitted and imposed against Y 'alize the force of the liquid thereon, said such relation to said contact members that the pressure transmit-ted in an upward direction through the liquid opposed by said partition, and a force exterted on the housing in opposition to the downward force exerted on the bottom thereof and the stresses exerted upon the supporting structure are thereby neutralized.

l0. A circuit interruptor comprising a tank containing a quenching liquid, a cover for the tank, bolts securing the cover and tank, separable contact members in said tank, a partition car ried by the cover and disposed below and substantially parallel to the surface of the liquid7 said liquid developing a high pressure when decomposed by an arc drawn between said contact members whi'h. is imposed upwardly on the partition and downwardly on the tank bottom, and including said cover and said bolts for transmitting the upward torce of said pressure on the partition through said cover and said bolts to the tank bottom to neutralize the downward force thereon.

CHRISTIAN AALBORG. 

